1. Field of the Invention
The present invention relates to a pneumatic tire. More specifically, the present invention relates to a pneumatic tire having a wear indicator at the groove bottom of a main groove.
2. Description of Related Art
Conventionally, it is known a pneumatic tire formed with a wear indicator at the groove bottom of a main groove of a tread, wherein on at least one of main groove walls on both sides in the groove width direction of the wear indicator, at least one projection is provided which forms a recess opened into a tread surface (for instance, see JP 2010-234559 A).
It is known another pneumatic tire formed with a wear indicator at the groove bottom of a main groove of a tread, wherein recesses are provided in the front and rear groove bottoms in the tire circumferential direction of the wear indicator or in the left and right groove walls of the wear indicator (for instance, see JP 2002-22514 A).
It is known a further pneumatic tire formed with a wear indicator at the groove bottom of a main groove of a tread, wherein small slots are formed on both sides of the wear indicator (for instance, see JP 5-178021 A).
However, in the pneumatic tire described in JP 2010-234559 A, the appearance is deteriorated since the recess is required to be opened into the tread surface.
In addition, in the pneumatic tire described in JP 2002-22514 A, cracks are likely to be caused from the recesses formed in the main groove.
Further, in the pneumatic tire described in JP 5-178021 A, due to the large occupied volume of the wear indicator, bare (surface exposition of the unvulcanized rubber material caused by rubber flow failure) occurs at the time of vulcanization, which can deteriorate the appearance.